Downhole to surface communications platform for drilling applications

Abstract

A drilling assembly for downhole to surface communications is provided. The drilling assembly includes a series of pipe segments coupled in fluid communication between a slip ring assembly and an end pipe portion. The slip ring assembly is coupled in data and fluid communication with the pipe segments. A surface communications link is in data communication with the drilling assembly via the slip ring assembly. An end pipe portion is coupled with the drilling assembly that includes an electronics assembly with electronic components for transferring data to the slip ring assembly via the drilling assembly. A drill bit is operably coupled with the end pipe portion for drilling a borehole. Each pipe segment includes an outer conductor portion, a hollow inner conductor portion, and a dielectric portion for electrical isolation between the outer conductor portion and the inner conductor portion.

Description

BACKGROUND OF THE INVENTION

The application generally relates to communications platforms and systems. The application relates more specifically to communications platforms and systems to provide a data link between downhole sensors and surface equipment in drilling installations.

Drilling technology has advanced recently to allow boreholes extending over great distances. Operators require accurate data on environmental operating parameters in deep boreholes. Communication systems with sensitive electronic sensors and circuitry are difficult to install and maintain in such harsh environments. Fluid conduits carry cooling fluid to the drill head through drill segments, are subject to leakage and may be corrosive to sensitive electronics equipment. Providing a continuous sealed conduit for fluid while transmitting data to the surface presents a significant challenge.

What is needed is a system and/or method that satisfies one or more of these needs or provides other advantageous features. Other features and advantages will be made apparent from the present specification. The teachings disclosed extend to those embodiments that fall within the scope of the claims, regardless of whether they accomplish one or more of the aforementioned needs.

SUMMARY OF THE INVENTION

One embodiment relates to a drilling assembly for downhole to surface communications. The drilling assembly includes a series of pipe segments coupled in fluid communication between a slip ring assembly and an end pipe portion. The slip ring assembly is coupled in data communication and in fluid communication with the pipe segments. A communications link is located at the surface of the drill hole, in data communication with the drilling assembly via the slip ring assembly. An end pipe portion is coupled with the last pipe segment of the drilling assembly at the bottom of the drill hole. The end pipe portion includes an electronics assembly having electronic components for transferring data to the slip ring assembly via the drilling assembly. A drill bit is operably coupled with the end pipe portion for drilling a borehole. Each pipe segment includes an outer conductor portion, a hollow inner conductor portion, and a dielectric portion for electrical isolation between the outer conductor portion and the inner conductor portion.

Another embodiment relates to a pipe segment for a drilling assembly. The pipe segment includes an outer conductor portion, a hollow inner conductor portion, and a dielectric portion for electrical isolation between the outer conductor portion and the inner conductor portion. The inner conductor portion defines a sealed fluid passage through the drilling assembly.

Another embodiment relates to an electronics assembly for a downhole to surface communications system for a drilling assembly. The electronics assembly includes a first end connection to a pipe segment of the drilling assembly. A second end is connected to a drill bit. A data link is included for communicating data between the electronics assembly and a surface communications link. The electronics assembly also has a radio frequency transceiver, a specialty drill pipe, and a radio frequency receiving means for extracting a data signal.

An advantage is the present system is a design and assembly of a drill pipe that conducts radio frequency (RF) signals.

Another advantage is a drill pipe for transmitting alternating current (AC) and direct current (DC) signals from a downhole location to surface communications equipment.

Still another advantage is means of providing electrical power to the downhole sensors as well as signal transmission. Transmission frequencies can range from kilohertz (kHz) to megahertz (MHz) to enable data transfer rates that exceed existing technology employed in the downhole communications.

A slip-ring joint may be employed for electrical continuity between an inner conductor and the surface receiver in which the signal is extracted from the drill pipe through the slip ring assembly.

Alternative exemplary embodiments relate to other features and combinations of features as may be generally recited in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The application will become more fully understood from the following detailed description, taken in conjunction with the accompanying figures, wherein like reference numerals refer to like elements, in which:

FIG. 1 shows an exemplary drill pipe segment of the present invention.

FIG. 2 shows a block diagram of a drill pipe assembly with electronics.

FIG. 3 shows a detailed cross-sectional view of a drill pipe segment coupling.

FIG. 4 shows a transparent perspective view of an end pipe portion.

FIG. 5 shows an enlarged detail of sealed atmospheric chamber 35 in sub-surface electronics assembly.

FIG. 6 shows a detail of an exemplary slip-ring assembly of the drill pipe assembly of FIG. 2.

FIG. 7 shows a schematic diagram of the system electronics for transmitting data and power signals.

DETAILED DESCRIPTION OF THE INVENTION

Before turning to the figures which illustrate the exemplary embodiments in detail, it should be understood that the application is not limited to the details or methodology set forth in the following description or illustrated in the figures. It should also be understood that the phraseology and terminology employed herein is for the purpose of description only and should not be regarded as limiting.

Referring to FIG. 1, a drill pipe segment 10 has an outer conductor portion 12. Outer conductor portion 12 is made of conductive material, e.g., steel or a similarly conductive metal, a dielectric portion 14 disposed between an inner conductor portion 16 and outer conductor portion 12. Dielectric portion 14 insulates inner conductor portion 16 from outer conductor portion 12. Inner conductor 16 is a hollow cylindrical pipe which serves as an electrical conductor as well as a conduit for a controlled fluid path. A male coupler portion 13 is attached to each drill pipe segment 10 at one end, and a female coupler portion 15 is connected at an opposite end of drill pipe segment 10, to allow a continuous string of drill pipe segments to be interconnected in electrical, data and fluid communication.

Referring next to FIG. 2, multiple pipe segments 10 may be coupled in serial fluid communication to form a drilling assembly 100 that extends to desired drilling depths. A slip ring assembly 18 (FIG. 6) connects the drill pipe segments 10 that are mechanically coupled, e.g., via tapered threads as described in greater detail below, or by other suitable connection means. A communications link 20 is located at the surface and is in data communication with drill pipe assembly 100 through slip ring assembly 18. At the end of drill pipe assembly 100 in the downhole location opposite the surface, a drill bit 22 is coupled with an end pipe portion 24. End pipe portion 24 is coupled with drill pipe assembly 100 and transfers torque to drill bit 22 to bore the drill hole. End pipe portion 24 houses electronics with downhole sensors for collecting data and transmitting data communications to communications link 20 via drill pipe assembly 100.

Referring next to FIG. 3, drill pipe assembly 100 maintains continuity through drill pipe segments 10 via inner conductor 16. A compliant contact arrangement 32 is made of a conductive material that bridges a gap 28 between adjacent pipe joints 13, 15 to provide a sealed fluid path or conduit 30, and electrical conductivity between pipe segments 10. Contact arrangement 32 mates with an adjoining inner conductor portion 16 via contact arrangement 32. An O-ring 26 seals fluid around the contact arrangement. Contact arrangement 32 includes a center contact and insulator 14. A centralizing alignment ramp 34 is provided to ensure alignment and proper engagement between pipe segments 10 when coupled. This provides a more robust interface between the box-side center contact 32 and the conductor 16 in female coupler portion 15. In an alternate embodiment, a spherical interface may be configured in a conventional ball and socket arrangement between adjoining pipe segments 10, with a spring between contact arrangement 32 and inner conductor portion 16 to provide positive engagement force with the adjoining inner conductor 16.

Referring next to FIG. 4, a transparent perspective view of end pipe portion 24 is shown. End pipe portion 24 includes a sub-surface electronics assembly 36. Sub-surface electronics assembly 36 is a communication platform used to provide a data link between downhole electronics including by way of example and not limitation, navigation sensors, force and torque sensors, accelerometers, and surface equipment used to process data. Sub-surface electronics assembly 36 comprises a downhole radio frequency (RF) transceiver, a specialty drill pipe, and a surface radio frequency (RF) receiver that provides a means of extracting the signal. In an embodiment, communications from about a few MHz/MBit to about 500 m have a range of attenuation between 10 dB to 20 dB. In an exemplary embodiment, communications out to 5 kilometers (km) are available at reduced data rates from 100-500 kHz/kBit. Attenuation for a coaxial drill pipe assembly configured as shown in FIGS. 1 and 2 indicate acceptable levels for a length of 500 m and signal frequency of 5 MHz, for copper inner conductor portion 16, a steel outer conductor portion, and a polyvinyl chloride (PVC) dielectric portion 14. Attenuation at 500 m and 5 MHz is about 13 dB and 32 dB for PVC tan(d) 0.025 and 0.07, respectively.

Sub-surface electronics assembly 36 further includes an inertial measurement unit (IMU), hydrostatic pressure sensor and batteries. Additional electronics components may be provided as needed. Various combinations of electronics components described herein may be selected as appropriate for existing downhole environments. Further, a sealed atmospheric chamber 35 is integrated within sub-surface electronics assembly 36 to isolate electronic components 40 from fluid in flow path 30. Internal threads 39 provide connection means with external pipe segments 10 and drill bit 22.

FIG. 5 shows an enlarged detail of sealed atmospheric chamber 35 in sub-surface electronics assembly 36. Electronics components 40 are maintained in the sealed atmospheric chamber 35. An exemplary bulkhead assembly 38 couples flow path 30 at an offset connection, wherein flow path 30 is axially displaced between adjacent inner conductor portions 16. Springs 42 ensure positive engagement between inner conductor portions 16.

Referring now to FIG. 6, a slip-ring assembly 18 is shown. As discussed above with respect to FIG. 2, slip-ring assembly 18 provides the communication interface with communications link 20 at the surface of the borehole. An internal mandrel 44 rotates with pipe segment 10 and dielectric portion 14, and waveguide 46. A stationary sleeve portion 48 supports the rotary pipe segment 10. Slip-ring assembly 18 conveys signals from rotating waveguide to a stationary data port 50. Data port 50 provides the conductors to transmit and receive electronic communication signals between communications link 20 and downhole electronics module 24.

Referring next to FIG. 7, a system schematic diagram 70 is shown. Drill pipe assembly 100 is represented schematically as a coaxial line. Bias tee circuits 72 are connected at opposite ends of drill pipe assembly to transfer electrical power while sustaining RF signals. Variable gain amplifiers (not shown) may be required to accommodate for signal attenuation based on the length of drill pipe assembly 100. In an embodiment, a low noise amplifier may be provided for up-hole communications and a power amplifier for down-hole communications. Power amplifiers with two-way communication measure feedback to tune the gain of the variable gain amplifier. At bias tees 72, amplifiers 74 amplify input and output signals, respectively.

At an input terminal, or downhole location, an IMU 76 may include, e.g., a field programmable gate array (FPGA) and sensors. IMU 76 generates a signal to communications transmitter module 78 connected in series with IMU 76. A battery pack 80, e.g., 7.4 volt lithium battery, or super capacitor may be connected to a battery charger/monitor 82, provides regulated DC power to IMU 76 and communications transmitter module 78, and to input amplifier 74 and bias tee 72. A voltage divider R-C circuit 86 is connected to IMU 76, transmitter module 78, battery charger 82 and power regulators to provide charge power state feedback input. At the output terminal or upper surface location, coaxial drill pipe assembly 100 is connected to another bias tee circuit 72. The output signal of circuit 72 is amplified by amplifier 74, and inserted to a receiver communications module 88, in data communication with a computer 90. Bias tee 72 and power regulator 84 receive input power from a DC voltage source 92, e.g., 28 to 48 volts DC. Regulator 84 provides a regulated DC voltage from source 92 to receiver communications module 88 and amplifier 72. Battery pack 80 stores energy and is used when power is disconnected up-hole to allow the system to collect data without interruption, if required. When in use, the system may be configured with sleep mode to conserve energy until power is restored from the surface power source. In an exemplary embodiment, transmitter module 78 and receiver module 88 may be, e.g., an integrated transceiver, Model MAX 9947 manufactured by Maxim Integrated of San Jose, Calif., or other suitable RF communication board having wideband, e.g., kHz to MHz, operating frequency. In an exemplary embodiment, transceivers 78, 88 may be configured at 2.176 MHz operating frequency, with On-off keying, output power ranging from +7 to +12 dBm, and receiver power ranging from −15 to +5 dBm at 50 ohms (Ω). Supply voltage may be from 3 to 5.5 VDC with a 16-pin TQFN package. Data rates for transceivers 78, 88 may be available up to 115.2 kbps and transmitter power consumption of 160 mW.

While the exemplary embodiments illustrated in the figures and described herein are presently preferred, it should be understood that these embodiments are offered by way of example only. Accordingly, the present application is not limited to a particular embodiment, but extends to various modifications that nevertheless fall within the scope of the appended claims. The order or sequence of any processes or method steps may be varied or re-sequenced according to alternative embodiments.

The present application contemplates methods, systems and program products on any machine-readable media for accomplishing its operations. The embodiments of the present application may be implemented using an existing computer processors, or by a special purpose computer processor for an appropriate system, incorporated for this or another purpose or by a hardwired system.

It is important to note that the construction and arrangement of the downhole to surface communications platform for drilling, as shown in the various exemplary embodiments is illustrative only. Although only a few embodiments have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter recited in the claims. For example, elements shown as integrally formed may be constructed of multiple parts or elements, the position of elements may be reversed or otherwise varied, and the nature or number of discrete elements or positions may be altered or varied. Accordingly, all such modifications are intended to be included within the scope of the present application. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. In the claims, any means-plus-function clause is intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments without departing from the scope of the present application.

Claims

1. A drilling assembly, comprising: a plurality of pipe segments coupled in serial fluid communication, a slip ring assembly, and an end pipe portion;the slip ring assembly coupled in data communication and in the serial fluid communication with the plurality of pipe segments and a communications link;the communications link disposed at a surface above the drilling assembly and in the data communication with the slip ring assembly;the end pipe portion coupled to the plurality of pipe segments, the end pipe portion comprising an electronics assembly, the electronics assembly comprising one or more electronic components for transferring data between the end pipe portion and the slip ring assembly via the plurality of pipe segments; anda drill bit operably coupled with the end pipe portion for drilling a borehole;wherein each pipe segment of the plurality of pipe segments comprises an outer conductor portion that forms an outer surface of said each pipe segment, a hollow inner conductor portion, and a dielectric portion disposed between said outer conductor portion and said hollow inner conductor portion;the dielectric portion insulating said hollow inner conductor portion from electrical contact with the outer conductor portion;the hollow inner conductor portion defining a fluid communication pathway through the drilling assembly; andwherein the data is transferred between the end pipe portion and the slip ring assembly via the plurality of pipe segments by way of the hollow inner conductor portion;a compliant contact arrangement disposed between adjacent pipe segments of the drilling assembly, the compliant contact arrangement configured to seal a fluid path and conduct electrical signals between the adjacent pipe segments;wherein a first contact portion mateable with an adjoining inner conductor portion of a second contact portion;the first contact portion comprising a first center contact and a first insulator cooperative with a second center contact and a second insulator of the second contact portion when coupled; anda spherical interface having a ball and a first spring at a first end of said each pipe segment and a socket and a second spring at a second end of said each pipe segment, wherein the ball and the socket are positively engaged between respective adjoining hollow inner conductor portions.

2. The drilling assembly of claim 1, wherein the slip ring assembly comprises: a stationary sleeve portion supporting a rotatable internal mandrel;the internal mandrel connected with the to a said each pipe segment of the plurality of pipe segments;a first dielectric portion and a waveguide;the waveguide in a first data communication with a data port disposed on the sleeve portion;the data port comprising one or more conductors to transmit and receive electronic communication signals between the communications link and the electronics assembly; andthe internal mandrel coupled to the plurality of pipe segments to generate torque to the drill bit.

3. The drilling assembly of claim 1, wherein the outer conductor portion comprises a conductive material.

4. The drilling assembly of claim 1, wherein the electronics assembly comprises a data link between the electronics assembly, the electronics assembly further comprising a radio frequency transceiver, a specialty drill pipe, and a radio frequency receiving means for extracting a data signal.

5. The drilling assembly of claim 4, wherein the electronics assembly further comprises the one or more electronic components for generating a second data to a the communications link; the one or more electronic components selected from a navigation sensor, a force sensor, a torque sensor, an accelerometers, and surface equipment used to process the second data.

6. The drilling assembly of claim 5, wherein radio frequency communications are configured to 500 meters (m) with a range of attenuation between 10 dB to 20 dB.

7. The drilling assembly of claim 6, wherein the plurality of pipe segments extend up to 5 kilometers, and transmit frequencies are in a range of 100 kHz/kBit to 500 kHz/kBit with attenuation between 13 dB to 32 dB.

8. The drilling assembly of claim 1, wherein said each pipe segment comprises the first end having a male coupler portion, and the second end opposite the first end, the second end comprising a female coupler portion, wherein the adjacent pipe segments being continuously connected in the drilling assembly for the serial fluid communication and the data communication.

9. The drilling assembly of claim 8, wherein a female interface portion is configured at the first end and a male interface portion is configured at the second end;the female interface portion having a first tapered end co-operable with a second tapered end of the male interface portion to align the respective adjoining hollow inner conductor portions or respective connected drill segments.

10. A pipe segment for a drilling assembly comprising: an outer conductor portion forming an outer surface of the pipe segment, a hollow inner conductor portion defining a fluid flow passage therethrough, and a dielectric portion disposed between said outer conductor portion and said hollow inner conductor portion;the dielectric portion insulating the hollow inner conductor portion from electrical contact with the outer conductor portion;the hollow inner conductor portion defining the fluid flow passage to be sealed therethrough;wherein the pipe segment is capable of mating to a mirror image pipe segment to continuously form a the fluid flow passage therethrough the pipe segment and the mirror image pipe segment;a compliant contact arrangement disposed between the pipe segment and the mirror image pipe segment of the drilling assembly;the compliant contact arrangement configured to seal the fluid flow passage and conduct electrical signals between the pipe segment and the mirror image pipe segment; wherein a first contact portion of the pipe segment being mateable with an adjoining inner conductor portion of a second contact portion of the mirror image pipe segment; the first contact portion comprising a first center contact and a first insulator cooperative with a second center contact and a second insulator of the second contact portion when coupled, wherein data is transferred between the pipe segment and the mirror image pipe segment; anda spherical interface having a ball and a first spring at a first end of the pipe segment and a socket and a second spring at a second end of the pipe segment, wherein the ball and the socket are positively engaged by the first and second springs disposed between respective adjoining inner conductor portions.

11. The pipe segment of claim 10, further comprising: the first end having a male coupler portion, and the second end opposite the first end;the second end comprising a female coupler portion co-operable with an adjacent pipe segment for continuously connecting a the drilling assembly with the sealed fluid flow passage and data communication.

12. The pipe segment of claim 10, further comprising: a female interface portion disposed at the first end and a male interface portion disposed at the second end;the female interface portion having a first tapered end co-operable with a second tapered end of a second male interface portion of an adjacent pipe segment to align the hollow inner conductor portion of the pipe segment to an adjacent hollow inner conductor portion of the adjacent pipe segment to connect the pipe segment to the adjacent pipe segment in the sealed fluid flow passage and data communication with the adjacent pipe segment.

13. An electronics assembly for a downhole to surface communications system for a drilling assembly, the electronics assembly comprising: a first end configured for connection to a pipe segment of the drilling assembly, and a second end configured for connection to a drill bit; anda data link between the electronics assembly and a surface communications link, a radio frequency transceiver, a specialty drill pipe, and a radio frequency receiving means for extracting a data signal;wherein the data link from the electronics assembly connects from the electronics assembly to an inner conductor of the pipe segment of the drilling assembly, the inner conductor defining a fluid passage through the pipe segment; and wherein the pipe segment comprises an outer conductor that forms an outer surface of the pipe segment, and a dielectric disposed between the outer conductor and the inner conductor, the dielectric insulating the inner conductor from electrical contact with the outer conductor;a compliant contact arrangement disposed between the pipe segment and an adjacent pipe segment of the drilling assembly; the compliant contact arrangement configured to seal the fluid passage and conduct electrical signals between the pipe segment and the adjacent pipe segment; wherein a first contact portion of the pipe segment being mateable with an adjoining inner conductor portion of a second contact portion of the adjacent pipe segment; the first contact portion comprising a first center contact and a first insulator cooperative with a second center contact and a second insulator of the second contact portion when coupled, wherein data is transferred between the pipe segment and the adjacent pipe segment; anda spherical interface having a ball and a first spring at the first end of the pipe segment and a socket and a second spring at the second end of the pipe segment, wherein the ball and the socket are positively engaged by the first and second springs disposed between respective adjoining inner conductor portions.

14. The electronics assembly of claim 13, further comprising one or more electronic components for generating the data to a communications link;the one or more electronic components selected from a navigation sensor, a force sensor, a torque sensor, an accelerometers, and surface equipment used to process the data.

15. The electronics assembly of claim 14, wherein radio frequency communications parameters are configured from 5 MHz/MBit to 500 meters (m) with a range of attenuation between 10 dB to 20 dB.

16. The electronics assembly of claim 13, wherein the drilling assembly comprises a series of interconnected pipe segments to extend up to 5 kilometers, and transmit frequencies in a range of 100 kHz/kBit to 500 kHz/kBit with attenuation between 13 dB to 32 dB.